﻿using System;
using System.Web;
using Xpedite.Resources;
using Xpedite.Resources.Compressors;

/* Copyright (c) 2010 CBaxter
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, 
 * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 
 * IN THE SOFTWARE. 
 */

namespace Xpedite.WebAbstraction
{
  internal interface IWebResponse
  {
    void NotFound();
    void NotModified();
    void SendResource(IResource resource, ICompressor compressor);
  }

  internal class WebResponse : IWebResponse
  {
    private readonly HttpResponse _response;

    public WebResponse(HttpResponse response)
    {
      Verify.NotNull(response, "response");

      _response = response;
    }

    public void NotFound()
    {
      _response.StatusCode = 404;
      _response.StatusDescription = "Not Found";
    }

    public void NotModified()
    {
      _response.StatusCode = 304;
      _response.StatusDescription = "Not Modified";
    }

    public void SendResource(IResource resource, ICompressor compressor)
    {
      const Int32 MinutesPerYear = 525600;

      _response.Expires = MinutesPerYear;
      _response.ContentEncoding = resource.Encoding;
      _response.ContentType = resource.GetContentType();
      _response.Cache.SetCacheability(HttpCacheability.Public);
      _response.Cache.SetLastModified(EnsureLessThanCurrentDateTime(resource.LastModified));

      if (resource.Bytes.Length == 0)
        return;

      if (compressor.HasContentEncoding)
        _response.AppendHeader(WebResponseHeader.ContentEncoding, compressor.ContentEncoding);

      _response.AppendHeader(WebResponseHeader.Vary, WebRequestHeader.AcceptEncoding);
      _response.BinaryWrite(compressor.Compress(resource.Bytes));
    }

    private static DateTime EnsureLessThanCurrentDateTime(DateTime date)
    {
      DateTime utcDate = date.ToUniversalTime();
      DateTime utcNow = DateTime.UtcNow;

      return utcDate > utcNow ? utcNow.Date : utcDate;
    }
  }
}
